JPS60162275A - Form peeling device of image forming device - Google Patents

Abstract

PURPOSE:To prevent damage of a photosensitive band to separate a copy paper surely by coating the front end of a peeling claw, which separates the transferred copy paper from a photosensitive body, with a fluororesin. CONSTITUTION:An image is transferred to a copy paper P from a photosensitive body 1 in an electrophotographic copying machine by a transfer part 5, and the copy paper P passes a peeling corotron 6 and is carried by a belt 9 and reaches a fixing part 10 and is ejected to the outside of the machine. A form peeling device 11 is provided for the purpose of separating the copy paper, which is apt to wind around the photosensitive body 1, from the photosensitive body 1, and its front end is coated with a polytetrafluoroethylene 11. Thus, the front end of the form peeling device 11 is prevented from damaging the surface of the photosensitive body 1 to prevent degradation of picture quality, and the photosensitive paper P is separated surely.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a peeling device used to peel paper from a photoreceptor in an image forming apparatus using a photoreceptor, and particularly when performing reversal development. The present invention relates to a paper peeling device suitable for application to.

[Prior art]

Conventionally, as a device for peeling paper from a photoreceptor in a copying machine, etc., a peeling claw made of metal such as stainless steel, phosphor bronze, or beryllium copper is installed near the photoreceptor, and the photoreceptor runs on the tip of the peeling claw. There is a device that peels off the paper by bringing it into contact with the photoreceptor, but in such paper peeling devices, scratches occur on the photoreceptor due to friction between the photoreceptor and the peeling claw. In other words, the metal tip of the peeling claw repeatedly comes into direct contact with a specific part of the circumferential surface of the photoconductor, so if a certain number of copies are made, such as several thousand copies in a copying machine, the photoconductor may be damaged and the photoconductor may be damaged. Width 5-10μ on the body
A scratch with a depth of about 5 μm is formed, and as a result, as shown in FIG. If the photoreceptor is damaged in this way, the photoreceptor surface potential V in the image area, the photoreceptor surface potential VBK in the non-image area, and the developing bias voltage VB will have the same relationship as shown in the figure (Al). In the case of positive development (Secondly, even if the image area is affected, if the width is less than one toner particle, the image density will decrease and white spots will rarely become visible. , However, the above surface potentials Vl, VBK
In addition, in the case of negative development where the relationship between the developing bias voltage VB is as shown in the same figure (B), the non-image area is affected and a potential difference is generated in the developing direction, so scratches on the photoreceptor will be removed from the copy. This appears as a thin black line on the top, and is further emphasized by the fringe potential, significantly degrading the image quality of the copy.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and an object thereof is to prevent the occurrence of such scratches on the surface of the photoreceptor caused by the claws of the pieces 1411.

[Structure of the invention]

In order to achieve the above object, the present invention coats the tip of the peeling claw with a fluororesin such as tetrabutylene ethylene resin to prevent scratches on the photoreceptor due to friction between the photoreceptor and the peeling claw. This is what I did.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 2 shows the structure around the photoreceptor of a reversal development copying machine as an image forming apparatus to which the paper peeling device of the present invention can be applied, and FIG. It is an enlarged view.

In FIG. 1, (1) is a drum-shaped photoreceptor, which is made of, for example, a selenium-tellurium alloy in which a thin layer of tellurium oxide is formed on a layer of selenium. The photoreceptor (1) is supported to rotate in the direction of arrow a, and
A charging corotron (2) for charging the photoreceptor (1), an image forming device (3), and a developing device (4) are arranged around the photoreceptor (1), and these perform charging, exposure, and the process shown in FIG.
Negative development is performed in a state where the developing bias voltage (2) is set between the potential vnx of the non-image area and the potential v (2) of the image area as shown in B). Further, around the photoreceptor (1), there is a transfer corotron (5) for transferring onto copy paper after the above-mentioned development process, and a peeling corotron (6) for removing static electricity before peeling off the copy paper. At the same time, the copy paper after the transfer process is transferred to the surface of the photoreceptor (1) in contact with the surface of the photoreceptor (1) at a position between the peeling corotron (6) and the cleaning device (7) as shown in FIG. A paper peeling device (8) is installed which peels off the copy paper from the copy paper 00), so that the peeled copy paper is sent to the fixing device 00) via a conveyance mechanism (9).

Fig. 4 shows the main part of an embodiment of the present invention used as such a paper peeling device (8), and Fig. 4 fA)
As shown in , the tapered tip of the plurality of peeling claws +111 is coated with tetrafluoroethylene resin (PTFE) (trade name: Teflon) (121), and the tip portion with such coating is Photoreceptor (1)
surface. That is, for example, a peeling claw α1 with a thickness of 40 to 70 μm formed using stainless steel, phosphor bronze, beryllium copper, etc.
) as shown in Figure 4 (B).
By coating the tip with PTFE (17J) to a thickness of about 1.5 m, the copy paper can be peeled off without the metal part of the tip coming into direct contact with the photoreceptor (1). There is.

In this way, by coating the tip of the peeling claw (11J with PTFEf12), the friction between the photoconductor (1) and the peeling claw + It is possible to prevent the occurrence of scratches on the photoreceptor (1) caused by scratches on the photoreceptor (1), and it is possible to peel the copy paper from the surface of the photoreceptor (1) without scratching the photoreceptor (1). Since the charging characteristics of the photoreceptor (1) do not deteriorate compared to other parts, thin black lines due to scratches on the photoreceptor (1) will appear on the copy even in the case of negative development. This prevents the occurrence of black streaks in non-image areas.

Furthermore, as mentioned above, when the photoreceptor (1) is made of a selenium-tellurium alloy, the thin layer of tellurium oxide has the advantage of being able to retain charge well. If the surface of 1) is damaged, it will not only mean that the distance between the conductive support and the conductive support becomes smaller, but also that the above-mentioned advantage of being able to retain charge well will be halved. Since the peeling claw (111) having the above structure can prevent the occurrence of scratches on the photoreceptor (1), such features of the selenium-tellurium alloy photoreceptor (1) are not impaired.

In the above embodiment, a case was described in which PTFE (12) having a small friction coefficient was coated to prevent scratches on the photoreceptor (1) due to friction with the photoreceptor (1). It is not limited to this, but there are 4 other
Buttoned ethylene-6buttonated propylene copolymer resin (PE
P), or may be coated with a fluororesin such as trifluorochloroethylene resin (PCTFE).

〔Effect of the invention〕

As described above, the present invention can prevent scratches on the photoreceptor due to friction between the photoreceptor and the peeling nail, so the charging characteristics of the portion of the photoreceptor that comes into contact with the peeling nail will not deteriorate. Therefore, even in the case of negative development, there will be no non-image areas (two-point streaks) caused by scratches on the photoconductor, and deterioration in image quality can be prevented. It has features such as being able to extend the lifespan of the body.

[Brief explanation of the drawing]

FIG. 1 (- and (Bl is an explanatory diagram illustrating the reduction in charging characteristics due to scratches on the photoreceptor in the case of positive development and negative development,
Fig. 2 shows the structure around the photoreceptor of a reversal development copying machine, Fig. 3 is a partially enlarged view thereof, and Figs. 4 (A) and (B) show peeling in a paper peeling device according to an embodiment of the present invention. It is a top view and a side view which show a claw part. Symbol explanation (1)... Photoreceptor (8) Mountain... Paper peeling device αD... Peeling claw α2...4 Fluorinated ethylene resin patent applicant Fuji Xerox Co., Ltd. Company agent: Patent attorney Tomohiro Donakamura, same as Katsuo Naruse (A) (B) Figure 2, Figure 3 (A) (B) °11

Claims (1)

[Claims] 1. A paper peeling device for an image forming apparatus, characterized in that a tip of a peeling claw for peeling paper from a photoreceptor is coated with a fluororesin.